Frequency selective surfaces are useful in a number of applications. Such applications include radomes, canopies, and other aircraft structures and the receiving surfaces of satellite dishes. A surface may be made frequency selective by forming a pattern on the surface, for example, by applying a patterned metal layer to the surface. The accuracy of the frequency selectivity of the surface depends on the precision of the pattern formed on the surface. Any curvature in the surface complicates the pattern and makes the achievement of precise frequency selectivity extremely difficult. This is especially true in the case of complexly curved surfaces. Currently, there is no known method for patterning curved surfaces to achieve precise frequency selectivity in a cost effective manner.
One method that has been tried is splicing flat sheets of etched copper onto a complexly curved surface. This method has produced inadequate alignment of the elements of the pattern and resulting unacceptable inaccuracies in the overall pattern.